Discharge and restitution of secretory material in the rat parotid gland in response to isoproterenol

Summary The sequence of morphological events occurring during discharge and restitution of secretory material in the rat parotid in response to isoproterenol administration has been studied using the electron microscope. With the dose used, discharge of secretory granules began within 5 min following injection and was complete by 40 mim. Intracellular accumulation of normal-appearing secretory material became evident at 6 hours, and restitution of resting quantities of secretory material was achieved between 12 and 18 hours after injection. Cellular events occurring during secretory discharge and restitution are discussed.This project was supported by Training Grant No. 5-Ti-GH-326 and by Predoctoral Research Grant No. 1-F1-GM-32, 528-01, National Institutes of Health. I wish to express my gratitude to Dr. Henry S. di Stefano under whose directorship this project was carried out.